Construction of hydraulic lifting jacks



Jan. 8, 1924. 1,480,508

LQA.COLUS A CONSTRUCTION OF HYDRAULIC LIFTING JACKS Filed April 16 3Sheets-Sheet 1 1,480,508 1 A. coLLls CONSTRUCTION OF HYDRAULIC LIFTINGJACKS Filed April 16. 1921 5 Sheets- Sheet 2 /1 yf Z9 M 2725622 Zar' red70 rile?,

Jan. 8, 1924. 1,480,508

l.. A. coLLls CONSTRUCTION 0F HYDRAULIC LIFTING JACKS Filed April 16,1921 3 SheetS-Sheet 3 152562Z for 6.5? goed faz/J5 Patentedlan. 8, 1924.

- UNITED STATES LESLIE ALFRED COLLIS, OF PUTNEY, LONDON, ENGLND.

CONSTRUCTION F HYDRAULIC LIFTING JACKS.

Application led April 16, 1921. ASerial No. 461,993.

To allwkomitmay concern:

Be it known that LEsLiE ALFRED CoLLIs, a subject of the King of GreatBritain, residing at Putney, London, England, has invented certain newand useful Improvements in the Construction of Hydraulic Lifting Jacks,of which the'following is a specication.

The object of this invention is` to cion-V struct a hydraulic lifting oroperating jack orlike appliance in such a manner that theram can beeasily and readily operatcdby hand or power and the liquid releasedslowly so as to ensure an efficient lowering or return movement of theram and thus avoid all shocks, and I also provide means whereby when theram has re-ached the greatest movement desired any further movement isprevented thereby preventing strain on the apparatus. y For the purposeof my invention I construct the ram cylinder of a greater length than isnecessary for the movement of the ram and the cylinder on the Workingside of the cylinder is connected with the cylinder on the other side ofthe ram head by a passage Way controlled by two valves and a piston orplunger and connected with such passage way preferably between the twovalves is a cylinder carrying a pump plunger actuated by any suitablemechanism.

The valves and piston are constructed and positioned as follows, next tothe ram cylinder and in the passage way is a ball or other suitablevalve (which may be spring controlled) capable of being pressed upon itsseating by the pressure on the working side of the rain head such valvebeing positioned on one side of the connecting passage between the pumpplunger cylinder and the other valve which is preferably a disc valvecapable of being preed upon its seating by the pressure in the umpcylinder. This disc valve is provide with a stem on both sides, one stemon the side opposite to that of the ball valve riding in a hole of thepiston which rides in a tubular seating and controlling at some part ofits movement the passageway from the non-working end of the ram'cylinder. This piston is provided with a groove or grooves along itsouter periphery and also a stein passing through a gland and pro]ect1nfrom'the valves casing and spring contro led such piston being operableto actuate the valves for a slow return movement of the ram and its rod,`or instead of this particular construction of valves I may constructthe disc valve as a ball valve and employ a loose stem positionedbetween the two valves the piston acting upon one ball valve which inturn acts upon the other ball valve and 'instead of the piston beinggrooved it may be made of slightly smaller diameter.

@My invention will be clearly understood from the following descriptionaided by the annexed drawings in which Fi re 1 is a sectional elevationof the appliances. i

Figure 2 is a sectional elevation of the valve appliance on an enlargedscale.

Figure 3 is a sectionalelevation of a modified form of valve appliances.

Figures 4, 5 and 6 are plan, front and side elevation of a hydraulictruck embodying;` my invention.

igures 7 8 and 9 are fragmentary views' in side elevation and plan ofmodified mechanism employed for preventing overworking of the plunger."

According to this invention I form with or aflix to the front of thenon-liftin frame 1 of a hydraulic truck a casting or ame 2 to which issecured a rain cylinder 3 of great-v er length than is necessary for themovement of the ram and inside the ram cylinder 3 is positioned the ramhead 4 connected b a rod 5 through a suitable stuing 'box or gl'and 6with the front of the lifting platform 7 of the truck. f

The ram cylinder 3 on the working` side of the ram 4 is connected withthe cy inder on the other side bfy a passage Way 8,.,9 controlled by twovalves 10, l1 and a piston or plunger 12 working in a cylinder 13`connected with the passage ways 8, 9 and between the two valves 10, 11by a passage Way 14 the pump plunger 12 being actuated by any suitablemechanism..l

According to Figures 1 and 2 the valves 2. The ball valve 10 ts on aseating and is capable of being held thereto by the pressure in thepassage 8 from the working side of the ram head 4 and such valve may bespring controlled or be held in its passage by the bar 15.

The valve seating and passage way are formed in a plug 16 screwed into ahole in the casting 2 in which a smaller hole is formed leadin to thecylinder 3 and a pack# ing 17 is emp eyed to ensure a tight joint.

In an enlarged art of thehole in the casting 2 is screwedp another plug18 a packing 19 here being employed to ensure a tight 'oma J The end ofthis plug 18 is positioned some little distance from the plug 16 so asto provide a space or opening from the passage way 14 connecting thepump cylinder 13.

This plug is .formed with a hole through its centre, of two diameters,the larger containing a piston 20 carried by a rod 21 passing through af gland 22 and controlled by a spring 23 engaging the head 24 and thegland 22.

The plug has a series of holes 25 connecting the passage way 9 and thepiston 20 is of two diameters, .the smaller diameter being positionednext the passage way 9 in normal i condition.

The piston 20 is provided with a central bore in which is ositioned astem 26 which carries a disc'va ve 11 finding a seating on the end ofthe plug 18 such. valve 11 being positioned between the passage ways 8,9 and 14. The piston 2O is provided with grooves 28 elongitudinallythereof.

Instead of forming the valve mechanism as shown in Figures 1 and 2, lmay construct the whole mechanismaiixable in the casting 2 as oneunitthis being specially useful to enable Vthe valves to be got at forrepairs at any, time and this construction l show at Figure 3 and inefect the construction is the same as at Figure 2 with slight p peateduntil the ram 4 and its load is lifted alteration for instead ofemploying a stem 26 to the disc valve 11^ll employ a loose stem 26fitting in a skeleton bracket 29 and instead of employing a disc valve11 l employ a ball valvel and the piston 20 instead of bein formed 'with,grooves it may be made o slightly smaller diameter than the diameter ofthe hole so as to allow of slow passage of'liquid. v 1 y The plug 16 iformed with a collar 30 whichgis screwed to the plug 18 so that allfcrmoneunit,` if Y To operate .the pump plunger 12 any mechanism can beemployed andV in the drawings show one way that is to say the pumpplunger 12 is provided on its end with rant 32 pivoted to a box casing33 attached to the casting'2 and to which is pivotally connected aYreciprocating toothed rod 34 moving in a gland 35 and which meshes withthe toothed quadrant 32 the rod 34 being connected by a collar 36 to theoperating handle 37 this having a bent end 38 connected by a link 39 toa lug 40 on a ring 41 surrounding the gland 35 the rings 36 and 41freely revolving so that the handle can be actuated to reciprocate therod 34 at any position of the handle this being furthe assisted by thelink 39.

The piston head 24 rides against a wiper or cam 42 screwed to the axle43 riding in bearings 44 on the box casting 33 the other end of the axle43 having afoot lever 45 for the purpose hereafter described.

ln normal condition the ram head 4 is at the nonworking end of itslstroke `and the pump plunger 12 is at the end of its ressure stroke allthe ram cylinder 3 an the passage ways 8, 9, 14 being filled with the h,draulio medium, the spring controlled plston 20 is at one end of itsmovement and free of the passage way 9 whilst the valve 11 is normal theball valve 10 being retained upon its seat by the hydraulic medium leftintheend of the ram cylinder 3.

Now on a movement of the pump plunger 12 by actuating the handle 37 thehydraulic medium will be drawn from the non-working end of the ramcylinder 3 past the valvey 11 into the pump c linder 13 and on agreturnmovement' of t e pump plunger `12 the valve 11 will be closed and thehydraulic medium forced past the ball valve 10 into the working end ofthe ram cylinder 3 and acting upon the ram head 4 will move it andV itsrod 5 which passes through a gland 6 along its cylinder lifting theplatform 7. 0n a return movement of the pump plunger 12 the ball valvewill close and hold the hydraulic medium in the working end of the ramcylinder 3 whilst a fresh quantity of hydraulic medium will be drawninto the ump cylinder 13 and this operation is reopen it against thepressure when the hydraulic medium under pressure in the wor ing end ofthe ram cylinder passes the valves 10, 11A and by reason of the springcontrolled piston 2O closing the passage way 9 to the non-working end ofthe ram cylinder the hydraulic medium can only pass through the groovesor reduced diameter back to the non-working end of the cylinder slowlythus allowing the ram to lower slowly.

To prevent over working of the apparatus I provide the cylinder casingorcasting 3 with say a bell crank lever 46 carrying a rod 47 connected tothe spring controlled piston 20 so that when the' ram head 4 reaches itsfulll working distance a connection on the rams rod or the appliancebeing lifted or lifting platform 7 in the drawings Figure 6 the liftingplatform 7 will actuate the bell crank 46and this will actuate the lever45 and through the wiper 42 will press in the spring controlled piston20 and the valves 10, 11 and a release of the pressure in the workingend of the ram cylinder will be-eilected as just described, but so soonas the ram has moved a certain .distance backward the bell crank 46 will,the ball valve and th'e ram 4 will stop or instead of preventingoverworking of the apparatus by the means just described and especiallywhere the spring controlled pis- `ton 2O is parallel with the cylinder 3I may employ the devices shown in Figures 7, 8 and 9 in which the rod 47runs parallel with the cylinder 3 and has its lower end connectedto thebell crank 46 or may be left free for the lifting platform 7 to haveaction against. This rod is pivotally connected by an arm or lever 49carrying the cam 42 to a lug 50 on the cylinder 3 the arm or lever 49being pivoted to the lug 50 with the cam 42 in proximity to the head 24of the stem 21 of the spring controlled piston 20. Pivotally connectedto the rod 47 is lever 45 which is also pivoted to a lug 51 projectingfrom the frame 2 and such lever 45 carries two pedals 52, 52a.

The connection of the lever 45 to the lug 51 is by a bolt-53 having a Vprojection or projections engaging a V notch or notches 54 on the lever45 and such lever 45 is kept in contact with the head of the bolt 53 bya coiled spring 55 to normally keep the V notches and projections. inengagement as shown. v

Now as the lifting platform 7 is reaching the end of, its movement itpushes up the rod 47 a certain distance when the cam 42 willA ress inthespring controlled piston 20 suiiclently far to hold the valve 11 openand as the lever 45 is moved at the same time the V notches 54 areremoved from the V projections and the spring will hold the lever 45 andthe arm or lever 49 at the placed position and by reason of' only theopens the valve 10 and after the platform- 7 has been lowered a pressureon the pedal 52a will reverse the appliances and the platform can belifted.

v An'v means can be employed for actuating Ithe pump plunger and foractuating the spring controlled piston automatically.

My invention is specially applicable for lifting trucks and the like inwhich case the spring controlled piston can be ordinarily actuated by afoot lever 45 and the bell crank lever 46 by the lifting platform 7 andI prefer that the pump cylinder 3 and passage ways 8, 9, 14 be in onecasting with valves 10, 11 and piston 20 positioned in a plug or plugsfitted therein, the ram cylinder 3 and the gland 6 being attached to thecasting with a pipe 9 connecting the non-working end of the ram cylinder3 with the casting, the rams rod 5 being connected to theliftingplatform 7 a sprlng 48 surrounding the ram rod 5 being interposedbetween the lifting platform 7 and the gland 6 to assist in lowering theplatform when -there is no load on the platform.

By this invention I employ the ram cylinder 3 as the reservoir and suchycylinder 3 may be positioned in the same planeas v that in which theplatform travels when employed with transporters or lifting trucks.

In applying the hydraulic apparatus to ordinary lifting jacks the end ofthe ram rod 5 is provided with a foot and the casting 2 is lifted suchcastin lifting shoe, or the end o the ram rod5 can be supplied with alifting shoe the casting being secured to a stand.

What I do claim as my invention and desire to secure by Letters Patentis 1. Hydraulic l1fting jack comprising a ram cylinder containing a ramrod and of greater length than necessary for movement 2 carrying the,

ends of the ram cylinder, two valves and a piston controlling thepassage ways, the passage way from the working end. of the cylinderleading to one valve, the other passage way leading to between the othervalve and the piston, a pump with a passage way leading to between thetwo valves the pumping action taking the liquid from the nonworking endof the cylinder and passing itto the other end the piston being operableto move the valves and reduce the opening to the nonworking end of thecylinder to allow of slow movement of the ram within the ram cylinder toeject the liquid 2. Hydraulic lifting jack as claimed in In testimonywhereof I have hereunto set claim 1 providing means to operate the myhand in presence of two subscribing piston and open the valves torelease the wltnesses. pressure when the limit of movement is reachedv VILESLIEALFRE ooLLIs. 3. Hydraulic lifting jack .as claimed in'Witnesses: claim l providing the ram rod with a, lift- LYNWOOD A.GARDNER ing member. f HAROLD Colm GARDNER.

